This invention relates to a rigid and positive locating optical element mounting, and more particularly to such an optical element mounting which does not undergo stress or relative motion between the parts therein either with exposure to a predetermined range of temperature variation or when the surface upon which the mounting system is attached undergoes stress.
Optical systems operate in a realm of precision that is generally several orders of magnitude more severe than usual mechanical tolerances. Standard units of optical measure are related to the wave length of light, with 0.5 micrometers being a typical light wave length. Good optical systems are measured for optical performance in terms of fractions of a wave length of light, and may therefore be seen to be tightly toleranced. Angular orientations in a good optical system are held to a few arc seconds. The critical problem is to position optical elements to the required tolerances without deforming them by imparting stresses in the optical elements due to the mounting techniques. Once the initial stress free mounting is obtained the collateral problem of maintaining the optical alignment and optical surface geometry over wide ranges of mounting surface stress and temperature variation is encountered. It is desirable to obtain means for mounting optical elements which may be easily assembled in positive and rigid alignment and which thereafter will not be skewed from the original alignment by stress induced from any source.